Borate phosphor materials for use in lighting applications

ABSTRACT

Boron containing phosphor compositions having the formulas (1) M 3 Ln 2 (BO 3 ) 4  doped with at least one activator selected from the group of Eu 2+ , Mn 2+ , Pb 2+ , Ce 3+ , Eu 3+ , Tb 3+ , and Bi 3+  where M is at least one of Mg, Ca, Sr, Ba, or Zn, and Ln is at least one of Sc, Y, La, Gd, or Lu; (2) M 2−x M′ x (Al, Ga) 2−y (Si, Ge) y B 2 O 7−z N z :Eu 2+ , Mn 2+ , Pb 2+  where M′ is one or more of alkali metals Na and/or K, M″ is one or more of alkaline earth Mg, Ca, Sr, Ba or Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4; and z=x+y; (3) M′ 2−x+y′ M″ x−y′ (Al, Ga) 2−y (Si, Ge) y B 2 O 7−z−y′ N z X y :Eu 2+ , Mn 2+ , Pb 2+ , where M′ is one or more of alkali metals Na and/or K, M″ is one or more of alkaline earth metals Mg, Ca, Sr, Ba and/or Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4; z=x+y, X═F and/or Cl, and 0≦y′≦2; (4) M′ 2−x M″ x Al 2−y+y ′Si y−y′ B 2 O 7−z−y′ N z X y :Eu 2+ , Mn 2+ , Pb 2+ , where M′ and M″ are defined above, 0≦x≦2, 0≦y≦2, 0≦z≦4; z=x+y, X═F and/or Cl, and 0≦y′≦2; (5) M′ 2−x+x′ M″ x−x″ Al 2−y+y′ Si y−y′ B 2 O 7−z−x′−y′ N z X (x′+y′) :Eu 2+ , Mn 2+ , Pb 2+ , where M′ and M″ are defined above, 0≦x≦2, 0≦y≦2, 0≦z≦4; z=x+y, X═F and/or Cl, and 0≦y′≦2; (6) MAl 2 B 2 O 7 :Eu 2+ , Mn 2+ , Pb 2+ ; where M═Mg, Ca, Sr, Ba or Zn; (7) MAl 2−x Si x B 2 O 7−x N x :Eu 2+ , Mn 2+ , Pb 2+ , where M═Mg, Ca, Sr, Ba and/or Zn, and 0≦x≦2; and (8) MAl 2 B 2−x Si x O 7−x N x :Eu 2+ , Mn 2+ , Pb 2+ , where M═Mg, Ca, Sr, Ba and/or Zn, and 0≦x≦2. Also disclosed are light emitting devices including a light source and at least one of the above phosphor compositions.

BACKGROUND

The present exemplary embodiments relate to phosphor compositions and alighting apparatus employing these compositions. It finds particularapplication in conjunction with light emitting diodes, and will bedescribed with particular reference thereto. However, it is to beappreciated that the present exemplary embodiment is also amenable toother like applications.

Light emitting diodes (LEDs) are semiconductor light emitters often usedas a replacement for other light sources, such as incandescent lamps.They are particularly useful as display lights, warning lights andindicating lights or in other applications where colored light isdesired. The color of light produce by an LED is dependent on the typeof semiconducting material used in its manufacture.

Colored semiconductor light emitting devices, including light emittingdiodes and lasers (both are generally referred to herein as LEDs), havebeen produced from Group III-V alloys such as gallium nitride (GaN). Toform the LEDs, layers of the alloys are typically deposited epitaxiallyon a substrate, such as silicon carbide or sapphire, and may be dopedwith a variety of n and p type dopants to improve properties, such aslight emission efficiency. With reference to the GaN-based LEDs, lightis generally emitted in the UV and/or blue range of the electromagneticspectrum. Until quite recently, LEDs have not been suitable for lightinguses where a bright white light is needed, due to the inherent color ofthe light produced by the LED.

Recently, techniques have been developed for converting the lightemitted from LEDs to useful light for illumination purposes. In onetechnique, the LED is coated or covered with a phosphor layer. Aphosphor is a luminescent material that absorbs radiation energy in aportion of the electromagnetic spectrum and emits energy in anotherportion of the electromagnetic spectrum. Phosphors of one importantclass are crystalline inorganic compounds of very high chemical purityand of controlled composition to which small quantities of otherelements (called “activators”) have been added to convert them intoefficient fluorescent materials. With the right combination ofactivators and inorganic compounds, the color of the emission can becontrolled. Most useful and well-known phosphors emit radiation in thevisible portion of the electromagnetic spectrum in response toexcitation by electromagnetic radiation outside the visible range.

By interposing a phosphor excited by the radiation generated by the LED,light of a different wavelength, e.g., in the visible range of thespectrum may be generated. Colored LEDs are often used in toys,indicator lights and other devices. Manufacturers are continuouslylooking for new colored phosphors for use in such LEDs to produce customcolors and higher luminosity.

In addition to colored LEDs, a combination of LED generated light andphosphor generated light may be used to produce white light. The mostpopular white LEDs consist of blue emitting GaInN chips. The blueemitting chips are coated with a phosphor that converts some of the blueradiation to a complimentary color, e.g. a yellow-green emission.Together, the blue and yellow-green radiation produces a white light.There are also white LEDs that utilize a UV emitting chip and a phosphorblend including red, green and blue emitting phosphors designed toconvert the UV radiation to visible light.

One known yellow-whitish light emitting device comprises a bluelight-emitting LED having a peak emission wavelength in the nearUV-to-blue range (from about 315 nm to about 480 nm) combined with ayellow light-emitting phosphor, such as cerium doped yttrium aluminumgarnet Y₃Al₅O₁₂:Ce³⁺ (“YAG:Ce”). The phosphor absorbs a portion of theradiation emitted from the LED and converts the absorbed radiation to ayellow light. The remainder of the blue light emitted by the LED istransmitted through the phosphor and is mixed with the yellow lightemitted by the phosphor. A viewer perceives the mixture of blue andyellow light, which in most instances is perceived as a whitish-yellowlight.

Such systems can be used to make white light sources having correlatedcolor temperatures (CCTs) of >4500 K and color rendering indices (CRIs)ranging from about 75-82. While this range is suitable for manyapplications, general illumination sources usually require higher CRIsand lower CCTs.

Other white light LED lighting systems use a UV or visible light LEDchip along with a blend of red, green, and/or blue phosphors that can beefficiently excited by near-UV radiation to make white light. However, acontinuing need is felt for new phosphor compositions that display moreflexibility in emission color, higher CRI values, and lower CCTs thanthe currently available phosphors.

Thus, a continuing need exists for new phosphors for use in conjunctionwith UV and visible LED chips displaying high quantum efficiency toproduce both colored and white-light LEDs having a high CRI.

BRIEF DESCRIPTION

In accordance with one aspect of the present exemplary embodiment, thereis provided a light emitting device including a semiconductor lightsource and a phosphor composition including at least one of: (1)M₃Ln₂(BO₃)₄ doped with at least one activator selected from the group ofEu²⁺, Mn²⁺, Pb²⁺, Ce³⁺, Eu³⁺, Tb³⁺, and Bi³⁺ where M is at least one ofMg, Ca, Sr, Ba, or Zn, and Ln is at least one of Sc, Y, La, Gd, or Lu;(2) M_(2−x)M′_(x)(Al, Ga)_(2−y)(Si, Ge)_(y)B₂O_(7−z)N_(z):Eu²⁺, Mn²⁺,Pb²⁺ where M′ is one or more of alkali metals Na and/or K, M″ is one ormore of alkaline earth Mg, Ca, Sr, Ba or Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4; andz=x+y; (3) M′_(2−x+y′)M″_(x−y′)(Al, Ga)_(2−y)(Si,Ge)_(y)B₂O_(7−z−y′)N_(z)X_(y):Eu²⁺, Mn²⁺, Pb²⁺, where M′ is one or moreof alkali metals Na and/or K, M″ is one or more of alkaline earth metalsMg, Ca, Sr, Ba and/or Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4; z=x+y, X═F and/or Cl, and0≦y′≦2; (4)M′_(2−x)M″_(x)Al_(2−y+y′)Si_(y−y′)B₂O_(7−z−y′)N_(z)X_(y):Eu²⁺, Mn²⁺,Pb²⁺, where M′ and M″ are defined above, 0≦x≦2, 0≦y≦2, 0≦z≦4; z=x+y, X═Fand/or Cl, and 0≦y′≦2; (5)M′_(2−x+x′)M″_(x−x″)Al_(2−y+y′)Si_(y−y′)B₂O_(7−z−x′−y′)N_(z)X_((x′+y′)):Eu²⁺,Mn²⁺, Pb²⁺, where M′ and M″ are defined above, 0≦x≦2, 0≦y≦2, 0≦z≦4;z=x+y, X═F and/or Cl, and 0≦y′≦2; (6) MAl₂B₂O₇:Eu²⁺, Mn²⁺, Pb²⁺; whereM═Mg, Ca, Sr, Ba or Zn; (7) MAl_(2−x)Si_(x)B₂O_(7−x)M_(x):Eu²⁺, Mn²⁺,Pb²⁺, where M═Mg, Ca, Sr, Ba and/or Zn, and 0≦x≦2; and (8)MAl₂B_(2−x)Si_(x)O_(7−x)N_(x):Eu²⁺, Mn²⁺, Pb²⁺, where M═Mg, Ca, Sr, Baand/or Zn, and 0≦x≦2.

In a second aspect, there is provided a phosphor having the formulaM₃Ln₂(BO₃)₄ doped with at least one activator selected from the group ofEu²⁺, Mn²⁺, Pb²⁺, Ce³⁺, Eu³⁺, Tb³⁺, and Bi³⁺ where M is at least one ofMg, Ca, Sr, Ba, or Zn, and Ln is at least one of Sc, Y, La, Gd, or Lu.

In an third aspect, there is provided a phosphor having the formulaM_(2−x)M′_(x)(Al, Ga)_(2−y)(Si, Ge)_(y)B₂O_(7−z)N_(z):Eu²⁺, Mn²⁺, Pb²⁺where M′ is one or more of alkali metals Na and/or K, M″ is one or moreof alkaline earth Mg, Ca, Sr, Ba or Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4; and z=x+y.

In a fourth aspect, there is provided a phosphor blend including atleast one of (1) M₃Ln₂(BO₃)₄ doped with at least one activator selectedfrom the group of Eu²⁺, Mn²⁺, Pb²⁺, Ce³⁺, Eu³⁺, Tb³⁺, and Bi³⁺ where Mis at least one of Mg, Ca, Sr, Ba, or Zn, and Ln is at least one of Sc,Y, La, Gd, or Lu; (2) M_(2−x)M′_(x)(Al, Ga)_(2−y)(Si,Ge)_(y)B₂O_(7−z)N_(z):Eu²⁺, Mn²⁺, Pb²⁺ where M′ is one or more of alkalimetals Na and/or K, M″ is one or more of alkaline earth Mg, Ca, Sr, Baor Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4; and z=x+y; (3) M′_(2−x+y′)M″_(x−y′)(Al,Ga)_(2−y)(Si, Ge)_(y)B₂O_(7−z−y′)N_(z)X_(y):Eu²⁺, Mn²⁺, Pb²⁺, where M′is one or more of alkali metals Na and/or K, M″ is one or more ofalkaline earth metals Mg, Ca, Sr, Ba and/or Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4;z=x+y, X═F and/or Cl, and 0≦y′≦2; (4)M′_(2−x)M″_(x)Al_(2−y+y′)Si_(y−y′)B₂O_(7−z−y′)N_(z)X_(y):Eu²⁺, Mn²⁺,Pb²⁺, where M′ and M″ are defined above, 0≦x≦2, 0≦y≦2, 0≦z≦4; z=x+y, X═Fand/or Cl, and 0≦y′≦2; (5)M′_(2−x+x)M″_(x−x″)Al_(2−y+y′)Si_(y−y′)B₂O_(7−z−x′−y′)N_(z)X_((x′+y′)):Eu²⁺,Mn²⁺, Pb²⁺, where M′ and M″ are defined above, 0≦x≦2, 0≦y≦2, 0≦z≦4;z=x+y, X═F and/or Cl, and 0≦y′≦2; (6) MAl₂B₂O₇:Eu²⁺, Mn²⁺, Pb²⁺; whereM═Mg, Ca, Sr, Ba or Zn; (7) MAl_(2−x)Si_(x)B₂O_(7−x)N_(x):Eu²⁺, Mn²⁺,Pb²⁺, where M═Mg, Ca, Sr, Ba and/or Zn, and 0≦x≦2; and (8)MAl₂B_(2−x)Si_(x)O_(7−x)N_(x):Eu²⁺, Mn²⁺, Pb²⁺, where M═Mg, Ca, Sr, Baand/or Zn, and 0≦x≦2; and at least one additional phosphor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of an illumination system inaccordance with one embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of an illumination system inaccordance with a second embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view of an illumination system inaccordance with a third embodiment of the present invention.

FIG. 4 is a cutaway side perspective view of an illumination system inaccordance with a fourth embodiment of the present invention.

FIG. 5 is a graph showing the emission spectra of(Sr_(0.95)Eu_(0.05))₃Y₂(BO₃)₄ at an excitation wavelength of 405 nm.

FIG. 6 is a graph showing the emission spectra ofSr₃(Y_(0.95)Ce_(0.05))₂(BO₃)₄ at an excitation wavelength of 405 nm.

FIG. 7 is a graph showing the emission spectra ofSr₃Y_(1.9)Eu_(0.1)(BO₃)₄ at an excitation wavelength of 405 nm.

FIG. 8 is a graph showing the emission spectra of(Sr_(0.95)Eu_(0.05))₃Sc₂(BO₃)₄ at an excitation wavelength of 405 nm.

FIG. 9 is a graph showing the emission spectra ofSr₃(Y_(0.45)Sc_(0.5)Ce_(0.05))₂(BO₃)₄ at an excitation wavelength of 405nm.

FIG. 10 is a graph showing the emission spectra ofSr₃Sc_(1.9)Eu_(0.1)(BO₃)₄ at an excitation wavelength of 405 nm.

FIG. 11 is a graph showing the emission spectra of(Ca_(0.95)Mn_(0.05))₃Y₂(BO₃)₄ at an excitation wavelength of 405 nm.

FIG. 12 is a graph showing the emission spectra ofCa_(0.9)NaAlSiB₂O₅N₂:Mn²⁺ at an excitation wavelength of 405 nm.

FIG. 13 is a graph showing the emission spectra ofSr_(0.9)NaAlSiB₂O₅N₂:Eu²⁺ at an excitation wavelength of 405 nm.

FIG. 14 is a graph showing the emission spectra ofCa_(0.9)Si₂B₂O₅N₂:Mn²⁺ at an excitation wavelength of 405 nm.

FIG. 15 is a graph showing the emission spectra ofSr_(0.9)Si₂B₂O₅N₂:Eu²⁺ at an excitation wavelength of 405 nm.

DETAILED DESCRIPTION

Phosphors convert radiation (energy) to visible light. Differentcombinations of phosphors provide different colored light emissions. Thecolored light that originates from the phosphors provides a colortemperature. Novel phosphor compositions are presented herein as well astheir use in LED and other light sources.

A phosphor conversion material (phosphor material) converts generated UVor visible radiation to a different wavelength visible light. The colorof the generated visible light is dependent on the particular componentsof the phosphor material. The phosphor material may include only asingle phosphor composition or two or more phosphors of basic color, forexample a particular mix with one or more of a yellow and red phosphorto emit a desired color (tint) of light. As used herein, the term“phosphor material” is intended to include both a single phosphorcomposition as well as a blend of two or more phosphors unless otherwisenoted.

It was determined that an LED lamp that produces a bright-white lightwould be useful to impart desirable qualities to LEDs as light sources.Therefore, in one embodiment, a luminescent material phosphor conversionmaterial blend (phosphor blend) coated LED chip is disclosed forproviding white light. The individual phosphors and a phosphor blendincluding the individual phosphors convert radiation at a specifiedwavelength, for example radiation from about 250 to 550 nm as emitted bya near UV or visible LED, into a different wavelength visible light. Thevisible light provided by the phosphor blend (and LED chip if emittingvisible light) comprises a bright white light with high intensity andbrightness.

With reference to FIG. 1, an exemplary light emitting assembly or lamp10 is shown in accordance with one preferred structure of the presentinvention. The light emitting assembly 10 comprises a semiconductor UVor visible radiation source, such as a light emitting diode (LED) chip12 and leads 14 electrically attached to the LED chip. The leads 14 maycomprise thin wires supported by a thicker lead frame(s) 16 or the leadsmay comprise self supported electrodes and the lead frame may beomitted. The leads 14 provide current to the LED chip 12 and thus causethe LED chip 12 to emit radiation.

The lamp may include any semiconductor visible or UV light source thatis capable of producing white light when its emitted radiation isdirected onto the phosphor. The preferred emission of the LED chip inthe present invention will depend on the identity of the phosphors inthe disclosed embodiments. However, the emission of the LED willgenerally have a wavelength in the range from about 250 to about 550 nm,which corresponds to an emission ranging from UV to green. Typicallythen, the semiconductor light source comprises an LED doped with variousimpurities. Thus, the LED may comprise a semiconductor diode based onany suitable III-V, II-VI or IV-IV semiconductor layers and having anemission wavelength of about 250 to 550 nm.

Preferably, the LED may contain at least one semiconductor layercomprising GaN, ZnSe or SiC. For example, the LED may comprise a nitridecompound semiconductor represented by the formula In_(i)Ga_(j)Al_(k)N(where 0≦i; 0≦j; 0≦k and i+j+k=1) having an emission wavelength greaterthan about 250 nm and less than about 550 nm. Such LED semiconductorsare known in the art. The radiation source is described herein as an LEDfor convenience. However, as used herein, the term is meant to encompassall semiconductor radiation sources including, e.g., semiconductor laserdiodes.

Although the general discussion of the exemplary structures of theinvention discussed herein are directed toward inorganic LED based lightsources, it should be understood that the LED chip may be replaced by anorganic light emissive structure or other radiation source unlessotherwise noted and that any reference to LED chip or semiconductor ismerely representative of any appropriate radiation source.

The LED chip 12 may be encapsulated within a shell 18, which enclosesthe LED chip and an encapsulant material 20. The shell 18 may be, forexample, glass or plastic. Preferably, the LED 12 is substantiallycentered in the encapsulant 20. The encapsulant 20 is preferably anepoxy, plastic, low temperature glass, polymer, thermoplastic, thermosetmaterial, resin or other type of LED encapsulating material as is knownin the art. Optionally, the encapsulant 20 is a spin-on glass or someother high index of refraction material. Preferably, the encapsulantmaterial 20 is an epoxy or a polymer material, such as silicone. Boththe shell 18 and the encapsulant 20 are preferably transparent orsubstantially optically transmissive with respect to the wavelength oflight produced by the LED chip 12 and a phosphor composition 22(described below). In an alternate embodiment, the lamp 10 may onlycomprise an encapsulant material without an outer shell 18. The LED chip12 may be supported, for example, by the lead frame 16, by the selfsupporting electrodes, the bottom of the shell 18, or by a pedestal (notshown) mounted to the shell or to the lead frame.

The structure of the illumination system includes a phosphor composition22 radiationally coupled to the LED chip 12. Radiationally coupled meansthat the elements are associated with each other so radiation from oneis transmitted to the other. In a preferred embodiment, the phosphorcomposition 22 is a blend of two or more phosphors, as will be detailedbelow.

This phosphor composition 22 is deposited on the LED 12 by anyappropriate method. For example, a water based suspension of thephosphor(s) can be formed, and applied as a phosphor layer to the LEDsurface. In one such method, a silicone slurry in which the phosphorparticles are randomly suspended is placed around the LED. This methodis merely exemplary of possible positions of the phosphor composition 22and LED 12. Thus, the phosphor composition 22 may be coated over ordirectly on the light emitting surface of the LED chip 12 by coating anddrying the phosphor suspension over the LED chip 12. Both the shell 18and the encapsulant 20 should be transparent to allow light 24 to betransmitted through those elements. Although not intended to belimiting, in one embodiment, the median particle size of the phosphorcomposition may be from about 1 to about 10 microns.

FIG. 2 illustrates a second exemplary structure of the system. Thestructure of the embodiment of FIG. 2 is similar to that of FIG. 1,except that the phosphor composition 122 is interspersed within theencapsulant material 120, instead of being formed directly on the LEDchip 112. The phosphor (in the form of a powder) may be interspersedwithin a single region of the encapsulant material 120 or, morepreferably, throughout the entire volume of the encapsulant material.Radiation 126 emitted by the LED chip 112 mixes with the light emittedby the phosphor composition 122, and the mixed light appears as whitelight 124. If the phosphor is to be interspersed within the encapsulantmaterial 120, then a phosphor powder may be added to a polymerprecursor, loaded around the LED chip 112, and then the polymerprecursor may be cured to solidify the polymer material. Other knownphosphor interspersion methods may also be used, such as transferloading.

FIG. 3 illustrates a third exemplary structure of the system. Thestructure of the embodiment shown in FIG. 3 is similar to that of FIG.1, except that the phosphor composition 222 is coated onto a surface ofthe shell 218, instead of being formed over the LED chip 212. Thephosphor composition is preferably coated on the inside surface of theshell 218, although the phosphor may be coated on the outside surface ofthe shell, if desired. The phosphor composition 222 may be coated on theentire surface of the shell or only a top portion of the surface of theshell. The radiation 226 emitted by the LED chip 212 mixes with thelight emitted by the phosphor composition 222, and the mixed lightappears as white light 224. Of course, the structures of FIGS. 1-3 maybe combined and the phosphor may be located in any two or all threelocations or in any other suitable location, such as separately from theshell or integrated into the LED.

In any of the above structures, the lamp 10 may also include a pluralityof scattering particles (not shown), which are embedded in theencapsulant material. The scattering particles may comprise, forexample, Al₂O₃ particles such as alumina powder or TiO₂ particles. Thescattering particles effectively scatter the coherent light emitted fromthe LED chip, preferably with a negligible amount of absorption.

As shown in a fourth preferred structure in FIG. 4, the LED chip 412 maybe mounted in a reflective cup 430. The cup 430 may be made from orcoated with a reflective material, such as alumina, titania, or otherdielectric powder known in the art. A preferred reflective material isAl₂O₃. The remainder of the structure of the embodiment of FIG. 4 is thesame as that of any of the previous Figures, and includes two leads 416,a conducting wire 432 electrically connecting the LED chip 412 with thesecond lead, and an encapsulant material 420.

In a first embodiment, the phosphor composition includes a boratephosphor having the formula M₃Ln₂(BO₃)₄ doped with at least oneactivator selected from the group of Eu²⁺, Mn²⁺, Pb²⁺, Ce³⁺, Eu³⁺, Tb³⁺,and Bi³⁺ where M is at least one of Mg, Ca, Sr, Ba, or Zn, and Ln is atleast one of Sc, Y, La, Gd, or Lu. In this embodiment, the LED chippreferably has a peak emission in the range of from 200-500 nm, morepreferably from 220-410 nm. In the crystal arrangement, the divalentactivators are thought to be situated at the site where M atoms would bewhile the trivalent activators take the place of Ln atoms. Thus, in theabove formula, one or both of the M and Ln may be substituted with adopant.

Exemplary compounds of this embodiment include:(Sr_(0.95)Eu_(0.05))₃Y₂(BO₃)₄; Sr₃(Y_(0.95)Ce_(0.5))₂(BO₃)₄;Sr₃Y_(1.9)Eu_(0.1)(BO₃)₄; (Sr_(0.95)Eu_(0.05))₃Sc₂(BO₃)₄;Sr₃(Y_(0.45)Sc_(0.5)Ce_(0.05))₂(BO₃)₄; Sr₃Sc_(1.9)Eu_(0.1)(BO₃)₄; and(Ca_(0.95)Mn_(0.05))₃Y₂(BO₃)₄.

FIGS. 5-11 are graphs showing the emission spectra of various phosphorsaccording to the above first embodiment at an excitation wavelength of405 nm. FIG. 5 is a graph showing the emission spectra of(Sr_(0.95)Eu_(0.05))₃Y₂(BO₃)4. FIG. 6 is a graph showing the emissionspectra of Sr₃(Y_(0.95)Ce_(0.05))₂(BO₃)₄. FIG. 7 is a graph showing theemission spectra of Sr₃Y_(1.9)Eu_(0.1)(BO₃)₄. FIG. 8 is a graph showingthe emission spectra of (Sr_(0.95)Eu_(0.05))₃Sc₂(BO₃)₄. FIG. 9 is agraph showing the emission spectra ofSr₃(Y_(0.45)Sc_(0.5)Ce_(0.05))₂(BO₃)₄. FIG. 10 is a graph showing theemission spectra of Sr₃Sc_(1.9)Eu_(0.1)(BO₃)₄. FIG. 11 is a graphshowing the emission spectra of (Ca_(0.95)Mn_(0.05))₃Y₂(BO₃)₄.

In a second embodiment, the phosphor composition includes an oxide oroxynitride phosphor having the formula M′_(2−x)M′_(x)(Al, Ga)_(2−y)(Si,Ge)_(y)B₂O_(7−z)N_(z):Eu²⁺, Mn²⁺, Pb²⁺ where M′ is one or more of alkalimetals Na and/or K, M″ is one or more of alkaline earth Mg, Ca, Sr, Baor Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4; and z=x+y. In this embodiment, the LED chippreferably has a peak emission in the range of from 200-500 nm, morepreferably from 220-410 nm. Exemplary phosphors in this embodimentinclude Ca_(0.9)NaAlSiB₂O₅N₂:Mn²⁺; Sr_(0.9)NaAlSi₂B₂O₅N₂:Eu²⁺;Ca_(0.9)Si₂B₂O₅N₂:Mn²⁺; Sr_(0.9)Si₂B₂O₅N₂:Eu²⁺ and Na₂Si₂B₂O₅N₂.

FIGS. 12-15 are graphs showing the emission spectra of various phosphorsaccording to the above second embodiment at an excitation wavelength of405 nm. FIG. 12 is a graph showing the emission spectra ofCa_(0.9)NaAlSi₂B₂O₅N₂:Mn²⁺. FIG. 13 is a graph showing the emissionspectra of Sr_(0.9)NaAlSiB₂O₅N₂:Eu²⁺. FIG. 14 is a graph showing theemission spectra of Ca_(0.9)Si₂B₂O₅N₂:Mn²⁺. FIG. 15 is a graph showingthe emission spectra of Sr_(0.9)Si₂B₂O₅N₂:Eu²⁺.

In a third embodiment, the phosphor composition comprisesM′_(2−x+y′)M″_(x−y′)(Al, Ga)_(2−y)(Si,Ge)_(y)B₂O_(7−z−y′)N_(z)X_(y):Eu²⁺, Mn²⁺, Pb²⁺ where M′ is one or moreof alkali metals Na and/or K, M″ is one or more of alkaline earth metalsMg, Ca, Sr, Ba and/or Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4; z=x+y, X═F and/or Cl, and0≦y′≦2.

In a fourth embodiment, the phosphor composition comprisesM′_(2−x)M″_(x)Al_(2−y+y′)Si_(y−y′)B₂O_(7−z−y′)N_(z)X_(y):Eu²⁺, Mn²⁺,Pb²⁺, where M′ and M″ are defined above, 0≦x≦2, 0≦y≦2, 0≦z≦4; z=x+y, X═Fand/or Cl, and 0≦y′≦2.

In a fifth embodiment, the phosphor composition comprisesM′_(2−x+x′)M″_(x−x″)Al_(2−y+y)Si_(y−y′)B₂O_(7−z−x′y′)N_(z)X_((x′+y)):Eu²⁺,Mn²⁺, Pb²⁺, where M′ and M″ are defined above 0≦x≦2, 0≦y≦2, 0≦z≦4;z=x+y, X═F and/or Cl, and 0≦y′≦2.

In a sixth embodiment, the phosphor composition comprises MAl₂B₂O₇:Eu²⁺,Mn²⁺, Pb²⁺ where M═Mg,Ca,Sr,Ba and/or Zn.

In a seventh embodiment, the phosphor composition comprisesMAl_(2−x)Si_(x)B₂O_(7−x)N_(x):Eu²⁺, Mn²⁺, Pb²⁺, where M═Mg, Ca, Sr, Baand/or Zn, and 0≦x≦2.

In an eight embodiment, the phosphor composition comprisesMAl₂B_(2−x)Si_(x)O_(7−x)N_(x):Eu²⁺, Mn²⁺, Pb²⁺, where M═Mg, Ca, Sr, Baand/or Zn, and 0≦x≦2.

The above described phosphor compositions may be produced using knownsolution or solid state reaction processes for the production ofphosphors by combining, for example, elemental oxides, carbonates and/orhydroxides as starting materials. Other starting materials may includenitrates, sulfates, acetates, citrates, or oxalates. Thus, according toone method for producing the above described carbonates may be used as asource for alkali and alkaline earth metals, Al₂O₃ and AlN may be usedas a source of Al, H₃BO₃ may be used as a source of B, and SiO₂ andSi₃N₄ may be used as a source of Si. The source of N in an oxynitridephosphor could be AlN, or Si₃N₄. Alternately, coprecipitates of the rareearth oxides could be used as the starting materials for the REelements. In a typical process, the starting materials are combined viaa dry or wet blending process and fired in air or under a slightlyreducing atmosphere at from, e.g., 1000 to 1600° C.

A fluxing agent may be added to the mixture before or during the step ofmixing. This fluxing agent may be NH₄Cl or any other conventionalfluxing agent, such as a fluoride of at least one metal selected fromthe group consisting of terbium, aluminum, gallium, and indium. Aquantity of a fluxing agent of less than about 20, preferably less thanabout 10, percent by weight of the total weight of the mixture isadequate for fluxing purposes.

The starting materials may be mixed together by any mechanical methodincluding, but not limited to, stirring or blending in a high-speedblender or a ribbon blender. The starting materials may be combined andpulverized together in a bowl mill, a hammer mill, or a jet mill. If themixture is wet, it may be dried first before being fired under areducing atmosphere at a temperature from about 900° C. to about 1700°C., preferably from about 1000° C. to about 1600° C., for a timesufficient to convert all of the mixture to the final composition.

The firing may be conducted in a batchwise or continuous process,preferably with a stirring or mixing action to promote good gas-solidcontact. The firing time depends on the quantity of the mixture to befired, the rate of gas conducted through the firing equipment, and thequality of the gas-solid contact in the firing equipment. Typically, afiring time up to about 10 hours is adequate. The crucible containingthe mixture may be packed in a second closed crucible containinghigh-purity carbon particles and fired in air so that the carbonparticles react with the oxygen present in air, thereby, generatingcarbon monoxide for providing a reducing atmosphere when needed—e.g. inthe case of phosphors doped with Ce³⁺. Alternatively, the reducingatmosphere may comprise a reducing gas such as hydrogen, carbon monoxideor a combination thereof in a predetermined amount (e.g. 1%), andoptionally diluted with an inert gas such as nitrogen, argon, or acombination thereof.

These compounds may be blended and dissolved in a nitric acid solution.The strength of the acid solution is chosen to rapidly dissolve theoxygen-containing compounds and the choice is within the skill of aperson skilled in the art. Ammonium hydroxide is then added inincrements to the acidic solution. An organic base such asmethanolamine, ethanolamine, propanolamine, dimethanolamine,diethanolamine, dipropanolamine, trimethanolamine, triethanolamine, ortripropanolamine may be used in place of ammonium hydroxide.

The precipitate is filtered, washed with deionized water, and dried. Thedried precipitate is ball milled or otherwise thoroughly blended andthen calcined in air at about 400° C. to about 1600° C. for a sufficienttime to ensure a substantially complete dehydration of the startingmaterial. The calcination may be carried out at a constant temperature.Alternatively, the calcination temperature may be ramped from ambient toand held at the final temperature for the duration of the calcination.The calcined material is similarly fired at 1000-1600° C. for asufficient time under a reducing atmosphere such as H₂, CO, or a mixtureof one of theses gases with an inert gas, or an atmosphere generated bya reaction between a coconut charcoal and the products of thedecomposition of the starting materials to covert all of the calcinedmaterial to the desired phosphor composition.

While suitable in many applications alone with an appropriate LED chip,the above phosphors may be blended with each other or one or moreadditional phosphors for use in LED light sources. Thus, in anotherembodiment, an LED lighting assembly is provided including a phosphorcomposition comprising a blend of a phosphor from one of the aboveembodiments with one or more additional phosphors. When used in alighting assembly in combination with a green to near UV LED emittingradiation in the range of about 235 to 550 nm, the resultant lightemitted by the assembly will be a white light. In one embodiment, thephosphor composition comprises a blend of one of the above embodimentphosphors, as described above, with a blue and a green emitting phosphorand optionally one or more additional phosphors.

The relative amounts of each phosphor in the phosphor composition can bedescribed in terms of spectral weight. The spectral weight is therelative amount that each phosphor contributes to the overall emissionspectra of the phosphor blend. The spectral weight amounts of all theindividual phosphors should add up to 1. A preferred blend comprises aspectral weight of from 0.001 to 0.200 of a blue phosphor, from 0.001 to0.300 of a green phosphor, and the balance of the blend being one of theabove described phosphors. Any known blue and green phosphor suitablefor use in near-UV to green LED systems may be used. In addition, otherphosphors such as red, blue-green, yellow, or other color phosphors maybe used in the blend to customize the white color of the resultinglight. While not intended to be limiting, suitable phosphor for use inthe blend with the present invention phosphors include:

(Ba, Sr, Ca)₅(PO₄)₃(Cl, F, Br, OH):Eu²⁺, Mn²⁺, Sb³⁺

(Ba, Sr, Ca)BPO₅:Eu²⁺, Mn²⁺

(Sr, Ca)₁₀(PO₄)₆*nB₂O₃:Eu²⁺

2SrO*0.84P₂O₅*0.16B₂O₃:Eu²⁺

(Mg, Ca, Sr, Ba, Zn)₃B₂O₆:Eu²⁺

Sr₂Si₃O₈.2SrCl₂:Eu²⁺

Ba₃MgSi₂O₈:Eu²⁺

Sr₄Al₁₄O₂₅:Eu²⁺

BaAl₈O₁₃:Eu²⁺

(Ba, Sr, Ca)MgAl₁₀O₁₇:Eu²⁺, Mn²⁺

(Ba, Sr, Ca)Al₂O₄:Eu²⁺

(Y, Gd, Lu, Sc, La)BO₃:Ce³⁺, Tb³⁺

Ca₈Mg(SiO₄)₄Cl₂:Eu²⁺, Mn²⁺

(Ba, Sr, Ca)₂SiO₄:Eu²⁺

(Ba, Sr, Ca)₂(Mg, Zn)Si₂O₇:Eu²⁺

(Sr, Ca, Ba)(Al, Ga, In)₂S₄:Eu²⁺

(Y, Gd, Tb, La, Sm, Pr, Lu)₃(Al, Ga)₅O₁₂:Ce³⁺

(Ca, Sr)₈(Mg, Zn)(SiO₄)₄Cl₂:Eu²⁺, Mn²⁺

Na₂Gd₂B₂O₇:Ce³⁺, Tb³⁺

(Ba, Sr)₂(Ca, Mg, Zn)B₂O₆:K, Ce, Tb

(Gd, Y, Lu, La)₂O₃:Eu³⁺, Bi³⁺

(Gd, Y, Lu, La)₂O₂S:Eu³⁺, Bi³⁺

(Gd, Y, Lu, La)VO₄:Eu³⁺, Bi³⁺

(Ca, Sr)S:Eu²⁺

SrY₂S₄:Eu²⁺

CaLa₂S₄:Ce³⁺

(Y, Lu)₂WO₆:Eu³⁺, Mo⁶⁺

(Mg, Ca, Sr, Ba, Zn)_(v)(Si, Ge)_(y)N_((2v/3+4y/3)):Eu²⁺

(Mg, Ca, Sr, Ba, Zn)_(v)(Si, Ge)_(y)O_(z)N_((2v/3+4y/3+2z/3)):Eu²⁺

The ratio of each of the individual phosphors in the phosphor blend mayvary depending on the characteristics of the desired light output. Therelative proportions of the individual phosphors in the variousembodiment phosphor blends may be adjusted such that when theiremissions are blended and employed in an LED lighting device, there isproduced visible light of predetermined x and y values on the CIEchromaticity diagram. As stated, a white light is preferably produced.This white light may, for instance, may possess an x value in the rangeof about 0.30 to about 0.55, and a y value in the range of about 0.30 toabout 0.55. As stated, however, the exact identity and amounts of eachphosphor in the phosphor composition can be varied according to theneeds of the end user.

The phosphor composition described above may be used in additionalapplications besides LEDs. For example, the material may be used as aphosphor in a fluorescent lamp, in a cathode ray tube, in a plasmadisplay device or in a liquid crystal display (LCD). The material mayalso be used as a scintillator in an electromagnetic calorimeter, in agamma ray camera, in a computed tomography scanner or in a laser. Theseuses are meant to be merely exemplary and not exhaustive. A specificcontemplate use for the above phosphors is in a gas discharge lamp (e.g.a mercury discharge lamp) including a lamp envelope containing a pair ofelectrodes, an ionizable medium contained therein, and a layer of thephosphor on an inner surface of the lamp envelope.

The invention has been described with reference to various preferredembodiments. Modifications and alteration will occur to others upon areading and understanding of this specification. The invention isintended to include all such modifications and alterations insofar asthey come within the scope of the appended claims or the equivalentthereof.

1. A lighting apparatus for emitting white light comprising: asemiconductor light source; and a phosphor composition radiationallycoupled to the light source, the phosphor composition comprising aphosphor composition including at least one of: (A) M₃Ln₂(BO₃)₄ dopedwith at least one activator selected from the group of Eu²⁺, Mn²⁺, Pb²⁺,Ce³⁺, Eu³⁺, Tb³⁺, and Bi³⁺ where M is at least one of Mg, Ca, Sr, Ba, orZn, and Ln is at least one of Sc, Y, La, Gd, or Lu; (B)M′_(2−x)M′_(x)(Al, Ga)_(2−y)(Si, Ge)_(y)B₂O_(7−z)N_(z):Eu²⁺, Mn²⁺, Pb²⁺where M′ is one or more of alkali metals Na and/or K, M″ is one or moreof alkaline earth Mg, Ca, Sr, Ba or Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4; and z=x+y;(C) M′_(2−x+y′)M″_(x−y′)(Al, Ga)_(2−y)(Si,Ge)_(y)B₂O_(7−z−y′)N_(z)X_(y):Eu²⁺, Mn²⁺, Pb²⁺, where M′ is one or moreof alkali metals Na and/or K, M″ is one or more of alkaline earth metalsMg, Ca, Sr, Ba and/or Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4; z=x+y, X═F and/or Cl, and0≦y′≦2; (D)M′_(2−x)M″_(x)Al_(2−y+y′)Si_(y−y′)B₂O_(7−z−y′)N_(z)X_(y):Eu²⁺, Mn²⁺,Pb²⁺, where M′ and M″ are defined above, 0≦x≦2, 0≦y≦2, 0≦z≦4; z=x+y, X═Fand/or Cl, and 0≦y′≦2; (E)M′_(2−x+x′)M″_(x−x″)Al_(2−y+y′)Si_(y−y′)B₂O_(7−z−x′−y′)N_(z)X_((x′+y′)):Eu²⁺,Mn²⁺, Pb²⁺, where M′ and M″ are defined above, 0≦x≦2, 0≦y≦2, 0≦z≦4;z=x+y, X═F and/or Cl, and 0≦y′≦2; (F) MAl₂B₂O₇:Eu²⁺, Mn²⁺, Pb²⁺ whereM═Mg, Ca, Sr, Ba and/or Zn; (G) MAl_(2−x)Si_(x)B₂O_(7−x)N_(x):Eu²⁺,Mn²⁺, Pb²⁺, where M═Mg, Ca, Sr, Ba and/or Zn, and 0≦x≦2; or (H),MAl₂B_(2−x)Si_(x)O_(7−x)N_(x):Eu²⁺, Mn²⁺, Pb²⁺, where M═Mg, Ca, Sr, Baand/or Zn, and 0≦x≦2.
 2. The lighting apparatus of claim 1, wherein thelight source is a semiconductor light emitting diode (LED) emittingradiation having a wavelength in the range of from about 370 to about405 nm.
 3. The lighting apparatus of claim 2, wherein the LED comprisesa nitride compound semiconductor represented by the formulaIn_(i)Ga_(j)Al_(k)N, where 0≦i; 0≦j, 0≦K, and i+j+k=1.
 4. The lightingapparatus of claim 1, wherein the light source is an organic emissivestructure.
 5. The lighting apparatus of claim 1, wherein the phosphorcomposition is coated on the surface of the light source.
 6. Thelighting apparatus of claim 1, further comprising an encapsulantsurrounding the light source and the phosphor composition.
 7. Thelighting apparatus of claim 1, wherein the phosphor composition isdispersed in the encapsulant.
 8. The lighting apparatus of claim 1,further comprising a reflector cup.
 9. The lighting apparatus of claim1, wherein said phosphor composition further comprises one or moreadditional phosphor.
 10. The lighting apparatus of claim 9, wherein saidone or more additional phosphors are selected from the group consistingof (Ba, Sr, Ca)₅(PO₄)₃(Cl, F, Br, OH):Eu²⁺, Mn²⁺, Sb³⁺; (Ba, Sr,Ca)MgAl₁₀O₁₇:Eu²⁺, Mn²⁺; (Ba, Sr, Ca)BPO₅:Eu²⁺, Mn²⁺; (Sr,Ca)₁₀(PO₄)₆*nB₂O₃:Eu²⁺; 2SrO*0.84P₂O₅*0.16B₂O₃:Eu²⁺;Sr₂Si₃O_(8*2)SrCl₂:Eu²⁺; Ba₃MgSi₂O₈:Eu²⁺; Sr₄Al₁₄O₂₅:Eu²⁺;BaAl₈O₁₃:Eu²⁺; Sr₄Al₁₄O₂₅:Eu²⁺; BaAl₈O₁₃:Eu²⁺;2SrO-0.84P₂O_(5−0.16)B₂O₃:Eu²⁺; (Ba, Sr, Ca)MgAl₁₀O₁₇:Eu²⁺, Mn²⁺; (Ba,Sr, Ca)₅(PO₄)₃(Cl, F, OH):Eu²⁺, Mn²⁺, Sb³⁺; (Ba, Sr, Ca)MgAl₁₀O₁₇:Eu²⁺,Mn²⁺; (Ba, Sr, Ca)Al₂O₄:Eu²⁺; (Y, Gd, Lu, Sc, La)BO₃:Ce³⁺, Tb³⁺;Ca₈Mg(SiO₄)₄Cl₂:Eu²⁺, Mn²⁺; (Ba, Sr, Ca)₂SiO₄:Eu²⁺; (Ba, Sr, Ca)₂(Mg,Zn)Si₂O₇:Eu²⁺; (Sr, Ca, Ba)(Al, Ga, In)₂S₄:Eu²⁺; (Y, Gd, Tb, La, Sm, Pr,Lu)₃(Al, Ga)₅O₁₂:Ce³⁺; (Ca, Sr)₈(Mg, Zn)(SiO₄)₄Cl₂:Eu²⁺, Mn²⁺ (CASI);Na₂Gd₂B₂O₇:Ce³⁺, Tb³⁺; (Ba, Sr)₂(Ca, Mg, Zn)B₂O₆:K, Ce, Tb; (Sr, Ca, Ba,Mg, Zn)₂P₂O₇:Eu²⁺, Mn²⁺ (SPP); (Ca, Sr, Ba, Mg)₁₀(PO₄)₆(F, Cl, Br, OH):Eu²⁺, Mn²⁺; (Gd, Y, Lu, La)₂O₃:Eu³⁺, Bi³⁺; (Gd, Y, Lu, La)₂O₂S:Eu³⁺,Bi³⁺; (Gd, Y, Lu, La)VO₄:Eu³⁺, Bi³⁺; (Ca, Sr)S:Eu²⁺; SrY₂S₄:Eu²⁺;CaLa₂S₄:Ce³⁺; (Ca, Sr)S:Eu²⁺; 3.5 MgO*0.5 MgF₂*GeO₂:Mn⁴⁺; (Ba, Sr,Ca)MgP₂O₇:Eu²⁺, Mn²⁺; (Y, Lu)₂WO₆:Eu³⁺, Mo⁶⁺; (Ba, Sr,Ca)_(x)Si_(y)N_(z):Eu²⁺.
 11. The lighting apparatus of claim 1, whereinsaid phosphor is selected from the group consisting of(Sr_(0.95)Eu_(0.05))₃Y₂(BO₃)₄; Sr₃(Y_(0.95)Ce_(0.05))₂(BO₃)₄;Sr₃Y_(1.9)Eu_(0.1)(BO₃)₄; (Sr_(0.95)Eu_(0.05))₃Sc₂(BO₃)₄;Sr₃(Y_(0.45)Sc_(0.5)Ce_(0.05))₂(BO₃)₄; Sr₃Sc_(1.9)Eu_(0.1)(BO₃)₄; and(Ca_(0.95)Mn_(0.05))₃Y₂(BO₃)₄.
 12. The lighting apparatus of claim 1,wherein said phosphor is selected from the group consisting ofCa_(0.9)NaAlSiB₂O₅N₂:Mn²⁺; Sr_(0.9)NaAlSiB₂O₅N₂:Eu²⁺;Ca_(0.9)Si₂B₂O₅N₂:Mn²⁺; Sr_(0.9)Si₂B₂O₅N₂:Eu²⁺; and Na₂Si₂B₂O₅N₂: Eu²⁺.13. A phosphor having the formula M₃Ln₂(BO₃)₄ doped with at least oneactivator selected from the group of Eu²⁺, Mn²⁺, Pb²⁺, Ce³⁺, Eu³⁺, Tb³⁺,and Bi³⁺ where M is at least one of Mg, Ca, Sr, Ba, or Zn, and Ln is atleast one of Sc, Y, La, Gd, or Lu.
 14. The phosphor of claim 13,comprising at least one of (Sr_(0.95)Eu_(0.05))₃Y₂(BO₃)₄;Sr₃(Y_(0.95)Ce_(0.05))₂(BO₃)₄; Sr₃Y_(1.9)Eu_(0.1)(BO₃)₄;(Sr_(0.95)Eu_(0.05))₃Sc₂(BO₃)₄; Sr₃(Y_(0.45)Sc_(0.5)Ce_(0.05))₂(BO₃)₄;Sr₃Sc_(1.9)Eu_(0.1)(BO₃)₄; and (Ca_(0.95)Mn_(0.05))₃Y₂(BO₃)₄.
 15. Aphosphor having the formula M′_(2−x)M′_(x)(Al, Ga)_(2−y)(Si,Ge)_(y)B₂O_(7−z)N_(z):Eu²⁺, Mn²⁺, Pb²⁺ where M′ is one or more of alkalimetals Na and/or K, M″ is one or more of alkaline earth Mg, Ca, Sr, Baor Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4; and z=x+y.
 16. The phosphor of claim 15comprising at least one of Ca_(0.9)NaAlSiB₂O₅N₂:Mn²⁺;Sr_(0.9)NaAlSiB₂O₅N₂:Eu²⁺; Ca_(0.9)Si₂B₂O₅N₂:Mn²⁺;Sr_(0.9)Si₂B₂O₅N₂:Eu²⁺; and Na₂Si₂B₂O₅N₂.
 17. A phosphor blendcomprising: (A) a first phosphor selected from the group consisting of(1) M₃Ln₂(BO₃)₄ doped with at least one activator selected from thegroup of Eu²⁺, Mn²⁺, Pb²⁺, Ce³⁺, Eu³⁺, Tb³⁺, and Bi³⁺ where M is atleast one of Mg, Ca, Sr, Ba, or Zn, and Ln is at least one of Sc, Y, La,Gd, or Lu; (2) M_(2−x)M′_(x)(Al, Ga)_(2−y)(Si,Ge)_(y)B₂O_(7−z)N_(z):Eu²⁺, Mn²⁺, Pb²⁺ where M′ is one or more of alkalimetals Na and/or K, M″ is one or more of alkaline earth Mg, Ca, Sr, Baor Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4; and z=x+y; (3) M′_(2−x+y′)M″_(x−y′)(Al,Ga)_(2−y)(Si, Ge)_(y)B₂O_(7−z−y′)N_(z)X_(y):Eu²⁺, Mn²⁺, Pb²⁺, where M′is one or more of alkali metals Na and/or K, M″ is one or more ofalkaline earth metals Mg, Ca, Sr, Ba and/or Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4;z=x+y, X═F and/or Cl, and 0≦y′≦2; (4)M′_(2−x)M″_(x)Al_(2−y+y′)Si_(y−y′)B₂O_(7−z−y′)N_(z)X_(y):Eu²⁺, Mn²⁺,Pb²⁺, where M′ and M″ are defined above, 0≦x≦2, 0≦y≦2, 0≦z≦4; z=x+y, X═Fand/or Cl, and 0≦y′≦2; (5)M′_(2−x+x′)M″_(x−x″)Al_(2−y+y)Si_(y−y′)B₂O_(7−z−x′−y′)N_(z)X_((x′+y′)):Eu²⁺,Mn²⁺, Pb²⁺, where M′ and M″ are defined above, 0≦x≦2, 0≦y≦2, 0≦z≦4;z=x+y, X═F and/or Cl, and 0≦y′≦2; (6) MAl₂B₂O₇:Eu²⁺, Mn²⁺, Pb²⁺; whereM═Mg, Ca, Sr, Ba or Zn; (7) MAl_(2−x)Si_(x)B₂O_(7−x)N_(x):Eu²⁺, Mn²⁺,Pb²⁺ where M═Mg, Ca, Sr, Ba and/or Zn, and 0≦x≦2; and (8),MAl₂B_(2−x)Si_(x)O_(7−x)N_(x):Eu²⁺, Mn²⁺, Pb²⁺ where M═Mg, Ca, Sr, Baand/or Zn, and 0≦x≦2; (B) and at least one additional phosphor.
 18. Aphosphor blend according to claim 17, wherein said at least oneadditional phosphor is selected from the group consisting of (Ba, Sr,Ca)₅(PO₄)₃(Cl, F, Br, OH):Eu²⁺, Mn²⁺, Sb³⁺; (Ba, Sr, Ca)MgAl₁₀O₁₇:Eu²⁺,Mn²⁺; (Ba, Sr, Ca)BPO₅:Eu²⁺, Mn²⁺; (Sr, Ca)₁₀(PO₄)₆*nB₂O₃:Eu²⁺;2SrO*0.84P₂O₅*0.16B₂O₃:Eu²⁺; Sr₂Si₃O_(8*2)SrCl₂:Eu²⁺; Ba₃MgSi₂O₈:Eu²⁺;Sr₄Al₁₄O₂₅:Eu²⁺; BaAl₈O₁₃:Eu²⁺; Sr₄Al₁₄O₂₅:Eu²⁺; BaAl₈O₁₃:Eu²⁺;2SrO-0.84P₂O_(5−0.16)B₂O₃:Eu²⁺; (Ba, Sr, Ca)MgAl₁₀O₁₇:Eu²⁺, Mn²⁺; (Ba,Sr, Ca)₅(PO₄)₃(Cl, F, OH):Eu²⁺, Mn²⁺, Sb³⁺; (Ba, Sr, Ca)MgAl₁₀O₁₇:Eu²⁺,Mn²⁺; (Ba, Sr, Ca)Al₂O₄:Eu²⁺; (Y, Gd, Lu, Sc, La)BO₃:Ce³⁺, Tb³⁺;Ca₈Mg(SiO₄)₄Cl₂:Eu²⁺, Mn²⁺; (Ba, Sr, Ca)₂SiO₄:Eu²⁺; (Ba, Sr, Ca)₂(Mg,Zn)Si₂O₇:Eu²⁺; (Sr, Ca, Ba)(Al, Ga, In)₂S₄:Eu²⁺; (Y, Gd, Tb, La, Sm, Pr,Lu)₃(Al, Ga)₅O₁₂:Ce³⁺; (Ca, Sr)₈(Mg, Zn)(SiO₄)₄Cl₂:Eu²⁺, Mn²⁺ (CASI);Na₂Gd₂B₂O₇:Ce³⁺, Tb³⁺; (Ba, Sr)₂(Ca, Mg, Zn)B₂O₆:K, Ce, Tb; (Sr, Ca, Ba,Mg, Zn)₂P₂O₇:Eu²⁺, Mn²⁺ (SPP); (Ca, Sr, Ba, Mg)₁₀(PO₄)₆(F, Cl, Br, OH):Eu²⁺, Mn²⁺; (Gd, Y, Lu, La)₂O₃:Eu³⁺, Bi³⁺; (Gd, Y, Lu, La)₂O₂S:Eu³⁺,Bi³⁺; (Gd, Y, Lu, La)VO₄:Eu³⁺, Bi³⁺; (Ca, Sr)S:Eu²⁺; SrY₂S₄:Eu²⁺;CaLa₂S₄:Ce³⁺; (Ca, Sr)S:Eu²⁺; 3.5 MgO*0.5 MgF₂*GeO₂:Mn⁴⁺; (Ba, Sr,Ca)MgP₂O₇:Eu²⁺, Mn²⁺; (Y, Lu)₂WO₆:Eu³⁺, Mo⁶⁺; (Ba, Sr,Ca)_(x)Si_(y)N_(z):Eu²⁺; and blends thereof.
 19. An arc discharge lamphaving an improved color rendering index for a given color coordinatedtemperature, the lamp comprising: a lamp envelope enclosing a dischargespace and having an inner surface; an ionizable medium within said lampenvelope comprising mercury and an inert gas; first and secondelectrodes; and a phosphor layer disposed on an inner surface of thelamp envelope comprising a phosphor composition including at least oneof: (A) M₃Ln₂(BO₃)₄ doped with at least one activator selected from thegroup of Eu²⁺, Mn²⁺, Pb²⁺, Ce³⁺, Eu³⁺, Tb³⁺, and Bi³⁺ where M is atleast one of Mg, Ca, Sr, Ba, or Zn, and Ln is at least one of Sc, Y, La,Gd, or Lu; (B) M′_(2−x)M″_(x)(Al, Ga)_(2−y)(Si,Ge)_(y)B₂O_(7−z)N_(z):Eu²⁺, Mn²⁺, Pb²⁺ where M′ is one or more of alkalimetals Na and/or K, M″ is one or more of alkaline earth Mg, Ca, Sr, Baor Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4; and z=x+y; (C) M′_(2−x+y′)M″_(x−y′)(Al,Ga)_(2−y)(Si, Ge)_(y)B₂O_(7−z−y′)N_(z)X_(y):Eu²⁺, Mn²⁺, Pb²⁺, where M′is one or more of alkali metals Na and/or K, M″ is one or more ofalkaline earth metals Mg, Ca, Sr, Ba and/or Zn, 0≦x≦2, 0≦y≦2, 0≦z≦4;z=x+y, X═F and/or Cl, and 0≦y′≦2; (D)M′_(2−x)M″_(x)Al_(2−y+y′)Si_(y−y′)B₂O_(7−z−y′)N_(z)X_(y):Eu²⁺, Mn²⁺,Pb²⁺, where M′ and M″ are defined above, 0≦x≦2, 0≦y≦2, 0≦z≦4; z=x+y, X═Fand/or Cl, and 0≦y′≦2; (E)M′_(2−x+x′)M″_(x−x′)Al_(2−y+y)Si_(y−y′)B₂O_(7−z−x′−y′)N_(z)X_((x′+y′)):Eu²⁺,Mn²⁺, Pb²⁺, where M′ and M″ are defined above, 0≦x≦2, 0≦y≦2, 0≦z≦4;z=x+y, X═F and/or Cl, and 0≦y′≦2; (F) MAl₂B₂O₇:Eu²⁺, Mn²⁺, Pb²⁺ whereM═Mg, Ca, Sr, Ba and/or Zn; (G) MAl_(2−x)Si_(x)B₂O_(7−x)N_(x):Eu²⁺,Mn²⁺, Pb²⁺, where M═Mg, Ca, Sr, Ba and/or Zn, and 0≦x≦2; or (H)MAl₂B_(2−x)S_(x)O_(7−x)N_(x):Eu²⁺, Mn²⁺, Pb²⁺, where M═Mg, Ca, Sr, Baand/or Zn, and 0≦x≦2.